Torque sensor component pairing and assembly

ABSTRACT

A system and method are provided related to replacing components of a fully assembled torque sensor system having been previously calibrated, whereby the new system with its new components, which may be installed in a larger system, can be recalibrated at the location where the component replacement or servicing occurs. Individual components are provided with individual characteristics information, either on or associated with the shipped component, so the end user may retrieve the information and enter it in the software, such as that associated with a control unit, which is used with the fully assembled torque sensor. A database storing information about each manufactured component and their respective characteristics information, and fully assembled systems and their collective characteristics information, may be maintained and accessible by end users.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to and claims the benefit of the filing dateof U.S. Provisional Application No. 62/347,407, entitled “Torque SensorComponent Pairing and Assembly,” which was filed on Jun. 8, 2016. Thecontents and disclosure of the same are incorporated herein byreference.

BACKGROUND OF THE INVENTION Field of Invention

The present invention relates to manufacturing torque sensor devices andsystems that incorporate torque sensor technology, and methods forassembling torque sensor components into an end product, which may be asubsystem integrated into a larger system.

Description of Related Art

An assembled torque sensor system may be described by reference to threebasic components: a shaft or disk having one or more integralmagnetically-conditioned regions, non-contact magnetic field sensorspositioned in proximity to the magnetically-conditioned regions, andassociated electronics components that in combination output anelectrical signal containing information representative of a measurablestate of the shaft or disk upon the application of a torque. Torquesensor systems of this type are available from, for example, MethodeElectronics, Inc., of Chicago, Ill., and are described in variouspatents, including, but not limited to, U.S. Pat. Nos. 6,260,423,8,087,304, and 8,836,458, the contents and disclosures of which areincorporated herein by reference in their entirety.

Referring to FIG. 1(a) from U.S. Pat. No. 6,260,423, shown therein is ashaft-type torque sensor device 2, which includes a transducer 4 and amagnetic field vector sensor 6. The transducer 4 includes one or moreaxially distinct, magnetically contiguous, oppositely polarized,circumferential bands or regions 8, 10 solely defining the magneticallyactive or transducer region of the shaft 12. The region 14 of the shaftto the left of A and the region 16 to the right of B are distinguishablefrom the active region only by the absence of any significant remanentmagnetization. The shaft 12 is typically formed of a ferromagnetic,magnetostrictive material having a particularly desirable crystallinestructure such that the active region will, likewise, be formed offerromagnetic, magnetostrictive material having the desired crystallinestructure. A torque 20 is shown being applied at one portion of theshaft 12 and is transmitted thereby to another portions of the shaft 12where the motion of the shaft 12 due to the torque 20 performs someuseful work. The torque 20 is shown as being in a clockwise directionlooking at the visible end of the shaft 12, but obviously can be appliedto rotate or tend to rotate the shaft in either or both directionsdepending on the nature of the machine incorporating the shaft 12.

The transducer 4 is magnetically polarized in a substantially purelycircumferential direction, as taught in U.S. Pat. Nos. 5,351,555 and5,520,059, the contents and disclosures of which are incorporated hereinby reference, at least to the extent that, in the absence of the torque20 (in a quiescent state), it has no net magnetization component in thedirection of axis 11 and has no net radial magnetization components. Theclosed cylindrical shape of the transducer 4 enhances the stability ofthe polarization by providing a complete magnetic circuit.

The magnetic field vector sensor 6 is a magnetic field vector sensingdevice located and oriented relative to the transducer 4 so as to sensethe magnitude and polarity of the field arising in the space about thetransducer 4 as a result of the reorientation of the polarizedmagnetization from the quiescent circumferential direction to a more orless steep helical direction upon application of the torque 20. Themagnetic field vector sensor 6 provides a signal output reflecting themagnitude of the torque 20. The magnetic field vector sensor 6 may be anintegrated circuit Hall effect sensor. The wires 24 connect magneticfield vector sensor 6 to a source of electrical current, and transmitthe signal output of the magnetic field vector sensor 6 to a receivingdevice (not shown), such as a control or monitoring circuit for themachine or system incorporating the shaft 12. A more detailed discussionof the types, characteristics, positioning and functioning of magneticfield vector sensors appears in at least the aforementioned U.S. Pat.Nos. 5,351,555 and 5,520,059; as well as in at least the aforementionedU.S. Pat. No. 8,087,304.

The two circumferentially polarized regions 8, 10 together constitutethe transducer's active region 4. The field sensor shown is centered onthe “wall” between the two oppositely polarized regions and is orientedto sense the radial field at this location. One or more magnetic fieldsensors may be utilized. In general, each such sensor would be locatednear the active region and oriented such that it is maximally efficientat sensing the field that arises when the shaft is transmitting torque.The similarity between this transducer and the more conventional designof U.S. Pat. Nos. 5,351,555 and 5,520,059 employing an active regionendowed with uniaxial circumferential anisotropy (“ring sensor”) isobvious.

Referring to FIG. 1(b) from U.S. Pat. No. 8,836,458, shown therein is aperspective drawing of a generally disk-shaped torque sensor device. Thedisk 110 is formed of ferromagnetic material and is, or at leastincludes, a magnetoelastically active region 140. The material selectedfor forming the disk 110 must be at least ferromagnetic to ensure theexistence of magnetic domains for at least forming a remanentmagnetization in the magnetoelastically active region 140, and must bemagnetostrictive such that the orientation of magnetic field lines inthe magnetoelastically active region 140 may be altered by the stressesassociated with applied torque. The disk 110 may be completely solid, ormay be partially hollow. The disk 110 may be formed of a homogeneousmaterial or may be formed of a mixture of materials. The disk 110 may beof any thickness, and is preferably between about 3 mm and about 1 cmthick.

The magnetoelastically active region 140 is preferably flat, andcomprises at least two radially distinct, annular, oppositely polarizedmagnetically conditioned regions 142, 144, defining themagnetoelastically active region 140 of the torque sensing device. Thetop and bottom surfaces 112, 114 do not have to be flat, however, asshown, but could have variable thickness in cross-section from thecenter of the disk 110 to the outer edge. Depending on the applicationfor which the torque sensing device is desired, it may be impractical toposition magnetic field sensors 152, 154 on both sides of the disk 110.Therefore, the magnetoelastically active region 140 may be present ononly one surface of the disk 110. However, the magnetoelastically activeregion 140 may also be present on both sides of the disk 110. One ormore magnetic field vector sensors may be positioned in proximity to themagnetically conditioned regions.

During operation of an exemplary torque sensor system of the kindidentified above and described below, a flux-gate magnetometer is usedto detect an applied magnetic field by utilizing thesaturation-characteristics of a ferromagnetic material in a magneticfield. An inductor possessing a core of ferromagnetic material willexhibit very non-linear changes to its inductance if this core isallowed to saturate. By detecting the presence of this non-linearbehavior, the magnetic field applied to the inductor can be inferred.

If one assumes use of an inductor with a core of ferromagnetic material,this inductor can be driven with a triangular alternating currentwaveform. The voltage waveform across the inductor will be approximatelya square wave, with an amplitude equal to L*dI/dt, where L is theinductance of the inductor, and dI/dt is the time rate-of-change of theapplied current waveform. As the inductor core saturates due to themagnetic flux within it resulting from the applied current waveform, theinductance of the inductor will drop dramatically. At this time, thevoltage waveform across the inductor will drop toward zero also.

If an ambient magnetic field exists, it will create a flux within theinductor core which will be additive with that applied by the excitationcurrent waveform. The result will be that the inductor will saturate ata different amplitude of excitation current between one polarity andanother. This will cause a distortion of the voltage waveform across theinductor containing a second harmonic term. By detecting the phase andamplitude of this second-harmonic component, the amplitude and directionof the ambient magnetic field can be determined.

In driving the flux-gates, it is generally intended that the flux-gatesspend time saturated in both directions so that the core does not buildup a magnetic offset. To achieve this, it is generally desired to use aclock source that feeds into a D-flip flop with both an output andinverted output. Going into a D-flip flop serves two purposes. One, itdivides the clock in half and two it provides a differential clocksignal. The differential clock signal can be fed into a pair of linedrivers to drive the flux-gates. One line driver is connected to oneside on the flux-gates and the other line driver is connected to theother side of the flux-gates. Driving the flux-gates in this mannermeans that for half the clock cycle the core is going into magneticsaturation in one direction. For the other half of the clock cycle thecore is going into magnetic saturation in the other direction.

Typically, a clock source may consist of an inverter with a Schmitttrigger input, a resistor and capacitor from the output to the input tocontrol the frequency of the clock signal. The clock signal can also beprovided by a microcontroller. The clock frequency and voltage can beset so that the flux-gates go far enough into saturation that theambient magnetic field does not prevent the flux-gates from achievingsaturation.

Generally, the fluxgates along with two resistors can be arranged in abridge configuration, which requires a minimum of two fluxgates tooperate the circuit. The centers of the fluxgates and the resistor arefeed into a pair of analog switches. This acts as a balanceddemodulator, operated at twice the coil excitation frequency, so thatthe output of these switches is a differential current whose amplitudeand polarity is proportional to the amplitude and phase of the secondharmonic content of the flux-gate voltage waveform. This current signalcan be integrated by an op-amp. The op-amp can produce an error signalthat can be fed back through a resistor into the center point betweenthe flux-gates. This closes the loop and keeps the system in control.The value of the feedback resistor can be used to control the responseof the circuit to ambient magnetic fields. The higher the resistor, thelarger the voltage response at the output of the integrator is to anambient magnetic field.

An error signal can be fed into a second-order multi-feedback low passfilter with adjustment for both swing and mean value. The adjustmentsfor the swing and mean value can be done using a digital potentiometer.With the gain potentiometer centered, the cutoff frequency can be 2.4kHz.

A monitor can be used to detect signals when the drive signal appears onthe center tap between the flux-gates. The reason for a drive signal onthe center tap, has to due with an open in a flux-gate. The center tapbetween the flux-gates is connected to an op-amp with diode, resistors,and capacitor make up a peak detect circuit. In normal operatingconditions, the value of the monitor can be a diode drop below thecenter tap voltage.

Generally, the electronics and the shaft/disk components of a torquesensor system like those identified above and their variants aremanufactured as a completed set in order to guarantee calibration. Thecompleted set ordinarily requires, as a final extra manufacturing stepat the point of manufacturing, calibration of the system. This canhinder post-manufacturing component servicing or replacement where partof the previously-calibrated set is altered or replaced with a newcomponent that has a different operating characteristic than theoriginal part, thereby potentially making the original calibrationinapplicable to the new set. It is, therefore, desirable to employ atorque sensor system that addresses the issues experienced when analtered or replaced component is added to an existing system, where thatcomponent has a different operating characteristic than the originalpart.

SUMMARY AND OBJECTS OF THE INVENTION

In the present invention, a shaft (or disk) like those mentioned above,having integrated magnetized portions, such as magnetoelastic sensingfeatures, is used to transmit an applied torque. Magnetic field sensorslike those mentioned above are used to sense a magnetic flux emanatingfrom the magnetized portions. Electronics like those mentioned above areused to receive, process, and output a signal representative of theapplied torque. Torque sensor systems of this type are usuallycalibrated as completed sets, which include all sensor components andconnecting cables that carry electronic signals between components.

A torque sensor system may be a combination of a shaft plus a sensorwith integrated electronics (i.e., two components), or it may be acombination of a shaft plus a sensor plus electronics (i.e., threecomponents). In the former case, the two components each have individualcalibrations; in the latter case, the three components each haveindividual calibrations. In each combination, the components may beproduced and calibrated at independent locations, then undergo a pairingprocedure whereby each component's characteristics have previously beenidentified, recorded, and are thereafter traceable so that a finalsystem calibration will not be necessary after the components are pairedtogether. This reduces the effort needed by the organization thatperforms the final assembly, and allows for interchangeable components,which is advantageous in the case of servicing (e.g., replacing)components.

To accomplish the pairing of a shaft (or a disk) component and magneticsensing components, each component (and their respective parts, asnecessary) may be marked, tagged, or otherwise indicated with a barcode,RFID chip, DMC, or other device, or indicated with a marking/taggingmethod, each having calibration parametric data (primarily sensitivityand offset) for that component.

Alternatively, the characteristics information for each component may bein the form of a unique number that allows identifying the componentcharacteristics stored in a database by cross-referencing the uniquenumber with the database records.

Either way, once components are combined in a final system, theindividual characteristics may be used by the system electronicssoftware to correct for the deviation of the individual components fromtheir targeted nominal values. For example, in the case of sensitivityand offset, correction factors (multiplication or division, forsensitivity, and addition or subtraction, for offset), may be applied bythe software. If the sensor electronics fail, one could know whichsensor (coils) and shaft are assembled in the customer system byreferencing the characteristics information.

By way of a specific, non-limiting example, an automotive transmissionmay incorporate, or include, a torque sensor system having three generalcomponents: a shaft (or disk), magnetic field sensors (usually fluxgatecoils), and electronics. If the electronics are provided with software,the software could perform various processes, such as (1) driving thefluxgate coils, (2) quantifying the magnetic field, and (3) providingcalibration parameters that “pair” the field sensors (with associatedelectronics) with the shaft. In that torque sensor system, both theshafts (disks) and the field sensor arrays may each have variations incertain operating parameters due to manufacturing tolerances, heattreatment, etc. There may also be variation in the electronics, and thuscorrection in most cases needs to happen at the system level from thecustomer, taking all three varying components into consideration.

To account for variations, assemblies sold as complete products(completely or partially assembled) are manufactured in a way that oneof the final steps is to apply a known torque value or range of valuesto the completed assembly, and then make a “zero” or offset adjustmentand a gain, or slope adjustment to the interface electronics. In someinstances, however, this approach may not be feasible, such as in thecase of automotive powertrain applications (for reasons known to thoseskilled in the art), and other automotive and non-automotive systemswhere components may need to be manufactured separately and combinedtogether later in the final product. Thus, for each component, themanufacturer may identify and record properties of each component of anassembly in a way that the information is then available when assemblingthe components into a final system.

In one aspect of the invention, the properties of the assembled systemare characterized to obtain the necessary offsets, which may be used tocompute adjustment factors for use in adjusting the system outputsignal(s).

As another option, the shaft (or the disk) properties may be measured bythe shaft (disk) manufacturer and recorded on a bar code, RFID chip, orother recording device that is associated with the shaft (disk), such asby hanging or fixing a tag or etching, etc., the bar code, RFID chip, orother recording device, or index number for cross-referencing records ina database, in or on the shaft (disk).

Similarly, the field sensor assembly properties may be measured by thefield sensor assembly manufacturer and recorded on a different bar code,RFID chip, or other recording device that is associated with the fieldsensor assembly.

When those components—the shaft or the disk with the field sensorassembly—are paired together later, the property values thus recordedare input into the sensor/interface electronics during a final pairingprocess at the assembly location, either manually or automatically,i.e., by scanning a bar code or interrogating RFID chips to obtain theinformation. In that way, any manufactured shaft (with its previouslyrecorded properties) may be paired to any manufactured sensor array(with its previously recorded properties) and may be paired to anymanufactured sensor electronics (with its previously recordedproperties).

In yet another aspect of the present invention, an algorithm of thesoftware may automatically calibrate the electronics or system levelelectronics control unit (ECU) without the organization responsible forcombining the components having to apply torque to the shaft (disk) toobtain the operating parameters of the final assembly.

In another aspect of the invention, the final calibration parameters areoffset and gain; however, other properties can also affect accuracy(e.g., hysteresis, rotational signal error (RSU), compassing, near fieldinterference, rotational signal, and temperature (temperaturecompensation, Tcomp, etc.), some of which are inherent properties, andare accounted for in the algorithm. Combined components may also haveunique characteristics, such as temperature compensation, and,therefore, identifying characteristics of individual and combinedcomponents are envisioned as part of the invention.

The present invention is useful in, for example, the automotive assemblyindustry in which a torque sensor system, which are made up of multiplecomponents, is employed in a vehicle or vehicle product such as agearbox.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) is a schematic perspective view of a prior art shaft-typetorque sensor system component;

FIG. 1(b) is a schematic perspective view of a prior art disk-typetorque sensor system component;

FIG. 2 is a schematic partial cross-sectional diagram of an assembledtorque sensor system, showing a shaft, magnetic field sensors, andelectronics components according to one aspect of the present invention;

FIG. 3 is a block flow diagram summarizing a method for making theassembled torque sensor system of FIG. 2;

FIG. 4 is a schematic partial cross-sectional diagram of the individualcomponents of and a final assembled torque sensor system, showing ashaft, magnetic field sensors, and electronics components according toanother aspect of the present invention;

FIG. 5 is a block flow diagram summarizing a method for making thecomponents and final assembled torque sensor system of FIG. 4;

FIG. 6 is a schematic partial cross-sectional diagram of the individualcomponents of and a final assembled torque sensor system, showing ashaft, magnetic field sensors, and electronics components according toanother aspect of the present invention;

FIG. 7 is a block flow diagram summarizing a method for making thecomponents and final assembled torque sensor system of FIG. 6;

FIG. 8 is a graph showing a calibration output signal from an assembledtorque sensor system; and

FIG. 9 is a schematic diagram of an individual component of the torquesensor system showing indicia attached to the component containinginformation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Several preferred embodiments of the invention are described forillustrative purposes, it being understood that the invention may beembodied in other forms not specifically described below and/or shown inthe drawings.

Turning first to FIG. 2, shown therein is a schematic partialcross-sectional diagram of an assembled torque sensor system 200,showing a shaft 202, non-contact magnetic field sensors 204 in proximityto the shaft 202, and electronics components 206 according to one aspectof the present invention.

In the embodiment shown, the assembled torque sensor system 200 may bemanufactured at a single location (i.e., “Location A”). The torquesensor system 200 may be shipped from “Location A” to the customer'sassembly location.

The shaft 202 may be rotatable or stationary. It has one or more(preferably two or three) magnetoelastic magnetized portions shown asfeatures 208, 210, which are axially-extending axial portions of theshaft 202. Each feature 208, 210 may be circumferentially magnetizedsuch that the magnetization in each portion is substantiallycircumferential in the direction shown (i.e., as indicated by the arrows208 a, 210 a).

One skilled in the art will appreciate that the shaft 202 may instead bea disk. The disk, like the shaft 202, may be rotatable or stationary.

A magnetized shaft (disk) 202, magnetic field sensors 204, andelectronics 206 components suitable for the present invention areavailable from Methode Electronics, in Chicago, Ill., USA, and aregenerally disclosed in one of several Methode patents, including, butnot limited to, those identified and described above such as U.S. Pat.Nos. 6,047,605, 8,087,304, and 8,635,917, the contents and disclosuresof which are incorporated herein by reference.

The shaft 202, magnetized as described above, and the magnetic fieldsensors 204 collectively exhibit or inherently possess certain magneticand magnetic field characteristics, including sensitivity, offset,hysteresis, rotational signal error (RSU), compassing, changes theretodue to near field interference, and changes thereto due to temperatureand other environmental or operating conditions. Definitions and/ordescriptions of each of those characteristics and/or parameters areprovided above and in the above-cited references and are well-known tothose skilled in the art. Those characteristics may be identifiedthrough testing and/or experimentation and thereafter associated withthat unique pairing of torque sensor system components.

In FIG. 2, the “Location A” may be a physical location, such as amanufacturing facility.

Turning now to FIG. 3, shown therein is a block flow diagram summarizinga method for making the assembled torque sensor system 200 of FIG. 1. Inthe method depicted therein, in which assembly into its final,completely-assembled form for later integration into a final product(such as an automobile) is performed at a single location, step 302involves production of the magnetic field sensors 204 and theelectronics components 206.

Step 304 involves magnetization of the shaft 202 as described andreferenced above.

Step 306, which is optional if digital electronics are available,involves loading a temperature compensation (Tcomp) algorithm into anECU of the magnetic field sensors 204.

Step 308 involves merging (e.g., through the various processes ofpositioning, arranging, orienting, connecting, fastening, assembling,attaching, etc.) the shaft 202 and magnetic field sensors andelectronics 204 into a final assembled product.

Step 310 involves storing or retrieving from storage characteristicsinformation or data concerning the final assembled product regarding itssensitivity, offset hysteresis, RSU, compassing, and near fieldinterference, and/or other parameters.

Step 312 involves providing the characteristics information to, ordetermining initial or updated characteristics information of the finalassembled product at or by, the end of line tester (EOLT). In this step,the information and data for step 310 is/are created.

Step 314 involves shipping or providing the final assembled productalong with the characteristics information determined at or by the EOLT.

Step 316 involves incorporating the final assembled product into anothersystem, such as an automotive transmission.

Step 318 involves storing or retrieving from storage characteristicsinformation or data concerning the final assembled product regarding itssensitivity, offset hysteresis, RSU, compassing, and near fieldinterference, and/or other parameters. The customer creates the samedata again.

Step 320 involves providing the characteristics information to ordetermining initial or updated characteristics information of the fullsystem at or by the EOLT of the customer.

Step 322 involves programming or updating the programming of theelectronic control unit that is used to control the full system (e.g.,transmission ECU).

Turning now to FIG. 4, shown therein is a schematic partialcross-sectional diagram of the individual components of and a finalassembled torque sensor system 200, showing a shaft 202, one or moremagnetic field sensors 204, and electronics component 206 according toanother aspect of the present invention. The magnetic field sensors 204,and the electronics components 206, which possess certaincharacteristics (as shown and described above), may be manufactured at afirst location (i.e., “Location A”) and then shipped to a customerassembly location (i.e., “Shipment A”). The shaft 202 component may bemanufactured at a second location (i.e., “Location B”) and then shippedto the customer assembly location (i.e., “Shipment B”). The twoshipments are then merged together at the customer assembly location(e.g., through the various processes of positioning, arranging,orienting, connecting, fastening, assembling, attaching, etc., theshipped components).

In FIG. 4, the “Location A” and the “Location B” could each be, forexample, a different physical location, such as different manufacturingfacilities owned by different entities in different states or countries.Or, the “Location A” and the “Location B” could each be a differentmanufacturing facility owned by the same entity but located at adifferent physical location, such as in different states or countries.Or, the “Location A” and the “Location B” could each be differentmanufacturing lines at a particular physical address owned by a singleentity. The two locations where the torque sensor system components aremade are not to be considered as being limited to any particularphysical distance separating where they are made, or who or what owns orcontrols the property at the locations where the components areseparately made.

As one non-limiting example of the above, an assembly location might bean automobile dealership service shop where automobiles are serviced(i.e., repaired, maintained, inspected, etc.). Automobiles equipped withassembled torque sensor systems could be repaired or otherwise servicedat the service shop. The dealership's parts department might carry instock or provide to the service shop one or more replacement magneticfield sensors 204, replacement electronics components 206, andreplacement shaft 202 components, each of which may have beenmanufactured at different locations and shipped to the dealership.

Turning now to FIG. 5, shown therein is a block flow diagram summarizinga method for making the components and final assembled torque sensorsystem 200 of FIG. 4. In the method shown, step 502 involves productionof the magnetic field sensors 204 and the electronics components 206 at,for example, “Location A”.

Step 504 involves production of the shaft 202 component as described andreferenced above at, for example, “Location B”.

Step 506, which is optional if digital electronics are available,involves loading a temperature compensation (Tcomp) algorithm into anECU of the magnetic field sensors 204.

Step 508 involves preferably storing (or retrieving from storage)characteristics information or data for the magnetic field sensors 204and the electronics components 206 assembly regarding its/theirsensitivity, offset, compassing, near field interference, temperaturecompensation, and/or other parameters.

Step 510 involves providing the characteristics information to, ordetermining initial or updated characteristics information of themagnetic field sensors 204 and the electronics components 206 assemblyat or by, the EOLT of the magnetic field sensors 204 and the electronicscomponents 206 assembly. In this step, the information and data for step508 is/are created.

Step 512 involves storing or retrieving from storage characteristicsinformation or data for the shaft 202 component regarding itssensitivity, offset, hysteresis, RSU, and/or other parameters.

Step 514 involves providing the characteristics information to, ordetermining initial or updated characteristics information of the shaft202 component at or by, the EOLT of the shaft 202 component. In thisstep, the information and data for step 512 is/are created.

Steps 516 and 518 involve marking (such as by etching), tagging,affixing to, etc., a device or unique identification number to themagnetic field sensors 204 and the electronics components 206 assemblyand to the shaft component, respectively. The device may be, forexample, a barcode etched to a surface feature of the assembly orcomponent, an RFID chip attached to the assembly or component, a uniqueidentification number marked on the assembly or component forcross-referencing a record in a database or memory of a computer device,or a tag containing written data.

Steps 520 and 522 involve shipping or providing the magnetic fieldsensors 204 and the electronics components 206 assembly (“Shipment A”)and the shaft 202 component (“Shipment B”), along with theircharacteristics information, to a customer assembly location.

Step 524 involves merging (e.g., through the various processes ofpositioning, arranging, orienting, connecting, fastening, assembling,attaching, etc.) the shaft 202 component and the magnetic field sensors204 and the electronics components 206 assembly into a final assembledproduct by the customer at the customer's assembly location.

Step 526 involves incorporating the final assembled product into anothersystem, such as an automotive transmission by the customer.

Step 528 involves obtaining the previously-determined characteristicsinformation from the device used to store, provide, or transmit thecharacteristics information for the shaft 202 component and the magneticfield sensors 204 and the electronics components 206 assembly.

Optionally, decision step 530 involves determining whether thetemperature compensation (Tcomp) algorithm requires adjustment based onthe previously-determined characteristics information for the shaft 202component and the magnetic field sensors 204 and the electronicscomponents 206 assembly.

If the temperature compensation algorithm requires updating, step 532involves programming or updating the programming of the electroniccontrol unit for the magnetic field sensors 204 or the system ECU.

If the temperature compensation algorithm does not require updating,step 534 involves programming or updating the programming of theelectronic control unit that is used to control the full assembledsystem (e.g., transmission ECU).

Step 536 involved optionally determining, as necessary, a system leveloffset after assembly and integration of the assembly into a largersystem.

Turning now to FIG. 6, shown therein is a schematic partialcross-sectional diagram of the individual components of and a finalassembled torque sensor system 200, showing a shaft 202, magnetic fieldsensors 204, and electronics components 206 according to another aspectof the present invention. The magnetic field sensors 204 may bemanufactured at a first location (i.e., “Location A”) and then shippedto a customer assembly location (i.e., “Shipment A”). The shaft 202component may be manufactured at a second location (i.e., “Location B”)and then shipped to the customer assembly location (i.e., “Shipment B”).The electronics 206 may be manufactured at a third location (i.e.,“Location C”) and then shipped to the customer assembly location (i.e.,“Shipment C”). The three parts may then be combined at the customer'sassembly location.

In FIG. 6, the “Location A,” the “Location B,” and the “Location C”could each be, for example, a different physical location, such asdifferent manufacturing facilities owned by different entities indifferent states or countries. Or, the “Location A,” the “Location B,”and the “Location C” could each be a different manufacturing facilityowned by the same entity but located at a different physical location,such as in different states or countries. Or, the “Location A,” the“Location B,” and the “Location C” could each be different manufacturinglines at a particular physical address owned by a single entity. Thethree locations where the torque sensor system components are made arenot be considered as being limited to any particular physical distanceseparating where they are made, or who or what owns or controls theproperty at the locations where the components are separately made.

Turning now to FIG. 7, shown therein is a block flow diagram summarizinga method for making the components and final assembled torque sensorsystem 200 of FIG. 6. In the method, step 702 involves production of themagnetic field sensors 204 at, for example, “Location A,” according tothe method described and referenced above.

Step 704 involves storing or retrieving from storage characteristicsinformation or data for the magnetic field sensors 204 regarding theirsensitivity, offset, compassing, near field interference, and/or otherparameters.

Step 706 involves providing the characteristics information to, ordetermining initial or updated characteristics information of themagnetic field sensors 204 at or by, the EOLT of the magnetic fieldsensors 204. In this step, the information and data for step 704 is/arecreated.

Step 708 involves marking (such as by etching), tagging, affixing to,etc., a device or unique identification number to the magnetic fieldsensors 204. The device may be, for example, a barcode etched to asurface feature of the magnetic field sensors 204, an RFID chip attachedto the magnetic field sensors 204, a unique identification number markedon the magnetic field sensors 204 for cross-referencing a record in adatabase or memory of a computer device, or a tag containing writtendata attached to the magnetic field sensors 204.

Step 710 involves shipping or providing the magnetic field sensors 204(i.e., “Shipment A”), along with the characteristics information, to acustomer assembly location.

Step 712 involves production of the electronics 206 at, for example,“Location C,” according to the method referenced above.

Step 714, which is optional if digital electronics are available,involves loading a temperature compensation (Tcomp) algorithm into anelectronic control unit (ECU) of the magnetic field sensors 204.

Step 716 involves storing or retrieving from storage characteristicsinformation or data for the electronics 206 regarding their sensitivity,offset, temperature compensation (Tcomp), and/or other parameters.

Step 718 involves providing the characteristics information to ordetermining initial or updated characteristics information of theelectronics 206 at or by the EOLT of the electronics 206. In this step,the information and/or data for step 716 is/are created.

Step 720 involves marking (such as by etching), tagging, affixing to,etc., a device or unique identification number to the electronics 206.The device may be, for example, a barcode etched to a surface feature ofthe electronics 206, an RFID chip attached to the electronics 206, aunique identification number marked on the electronics 206 forcross-referencing a record in a database or memory of a computer device,or a tag containing written data attached to the electronics 206.

Step 722 involves shipping or providing the electronics 206 (i.e.,“Shipment C”), along with the characteristics information, to a customerassembly location.

Step 724 involves production of the shaft 202 at, for example, “LocationB”) according to the method described and referenced above.

Step 726 involves storing or retrieving from storage characteristicsinformation or data for the shaft 202 regarding its sensitivity, offset,hysteresis, RSU, and/or other parameters.

Step 728 involves providing the characteristics information to ordetermining initial or updated characteristics information of the shaft202 at or by the EOLT of the shaft 202. In this step, the informationand/or data for step 728 is/are created.

Step 730 involves marking (such as by etching), tagging, affixing to,etc., a device or unique identification number to the shaft 202. Thedevice may be, for example, a barcode etched to a surface feature of theshaft 202, an RFID chip attached to the shaft 202, a uniqueidentification number marked on the shaft 202 for cross-referencing arecord in a database or memory of a computer device, or a tag containingwritten data attached to the shaft 202.

Step 732 involves shipping or providing the shaft 202 (i.e., “ShipmentB”), along with the characteristics information, to a customer assemblylocation.

Step 734 involves merging, at the customer assembly location, themagnetic field sensors 204 produced at “Location A”, the electronics 206produced at “Location C”, and the shaft 202 produced at “Location B”into a final assembled product (e.g., through the various processes ofpositioning, arranging, orienting, connecting, fastening, assembling,attaching, etc.).

Step 736 involves incorporating the final assembled product into anothersystem, such as an automotive transmission.

Step 738 involves obtaining the previously-determined characteristicsinformation from the device used to store, provide, or transmit thecharacteristics information for the shaft 202, the magnetic fieldsensors 204, and the electronics 206.

Decision step 740 involves determining whether the temperaturecompensation (Tcomp) algorithm for the sensor electronics 206 requiresadjustment based on the previously-determined characteristicsinformation.

If the temperature compensation algorithm requires updating, step 742involves programming or updating the programming of the electroniccontrol unit for the magnetic field sensors 204, or the system ECU inthe case where only pure analog electronics are available.

If the temperature compensation algorithm does not require updating,step 744 involves programming or updating the programming of theelectronic control unit that is used to control the full assembledsystem (e.g., transmission ECU).

Step 746 involved optionally determining, as necessary, a system leveloffset after assembly and integration of the assembly into a largersystem.

Turning next to FIG. 9, shown therein is a schematic diagram of a shaft202 component for use in the torque sensor system 200, where informationabout the component is provided with the component such as by etching,tagging, affixing to, etc., a device or unique identification number tothe shaft 202. As noted above, the device may be, for example, a barcode902 etched to a surface feature of the shaft 202. A barcode reader (notshown) could be used to scan the barcode 902 to cross referenceinformation stored in a memory device (not shown) that has beenpreviously associated with the component.

As also noted above, instead of a barcode 902, the information about thecomponent may be stored in an RFID chip (not shown) temporarily (andremovably) attached to the shaft 202, or a unique identification number(not shown) marked on the shaft 202 for cross-referencing a record in adatabase or memory of a computer device, or a tag containing writtendata temporarily (and removably) attached to the shaft 202. The barcode,RFID chip, ID number, or other information storage device or conveyingmethod may also be associated with or included with a package used totransport the component from one location to another.

EXAMPLE

For use in a gearbox torque sensor assembly system or some otherapplication, a shaft having ID No. 506 was paired with a magnetic fieldsensor having ID No. 105 and a printed circuit board electronics devicehaving ID No. 398. This pairing of components in a fully assembledsystem was then referred to as a master system.

Table 1 provides, and FIG. 8 shows, data reflecting certaincharacteristics of the master system. In particular, the sensor outputsignals (mV) was measured relative to varying amounts of applied torque(Nm) to the shaft component. The data in Table 1 and shown in FIG. 8thus are the calibration results of the master system against which allother combinations of components can be measured (calibrated) against.

As shown in Table 1 and FIG. 8, the offset of the master system (i.e.,the electronics output signal at zero applied torque) was determined tobe 2,479.0 mV. The gain (i.e., the change in output with applied torqueinput) was determined to be 2.0006 mV/Nm, with a factor (R²) equal to0.9999.

TABLE 1 Measurement Applied Torque Signal Output Point (Nm) (mV)Deviation (%) BFL 1 0 2470 −0.44 2 103 2678 −0.37 3 201 2876 −0.29 4 3003075 −0.21 5 402 3281 −0.10 6 502 3481 −0.06 7 398 3278 0.14 8 297 30800.30 9 200 2886 0.39 10 98 2683 0.40 11 0 2489 0.51 12 −100 2289 0.45 13−200 2084 0.31 14 −300 1883 0.21 15 −402 1678 0.13 16 −501 1478 0.07 17−403 1671 −0.14 18 −299 1877 −0.26 19 −200 2074 −0.31 20 −100 2273 −0.2921 0 2470 −0.44

Tables 2(a), 2(b), and 2(c) show measured data (inherentcharacteristics) for fifteen different assembled pairings of shafts,sensors, and electronics components. Pairing No. 1, shown in the tables,is the master system comprised of the combination of a reference shaft,a reference magnetic field sensor, and a reference electronic component,as described above.

Table 2(a) shows the measured data for the pairing of various shafts (IDNos. 502, 503, 504, 505, and 507) substituted for the reference shaft(ID No. 506(M)), combined with the reference magnetic field sensor (IDNo. 105(M)) and the reference electronic component (ID No. 398(M)).

Table 2(b) shows the measured data for the pairing of various magneticfield sensors (ID Nos. 101, 102, 103, 104, 106) substituted for thereference magnetic field sensors (ID No. 105(M)), combined with thereference shaft (ID No. 506(M)) and the reference electronic component(ID No. 398(M)).

Table 2(c) shows the measured data for the pairing of various electroniccomponents (ID Nos. 399, 401, 403, 404, 405) substituted for thereference electronic component (ID No. 398(M)), combined with thereference shaft (ID No. 506(M)) and the reference magnetic field sensorscomponent (ID No. 105(M)).

In the three tables 2(a), 2(b), and 2(c), the target slope was 2.0mV/Nm, the target offset was 2,500 mV at zero applied torque, and ageneral offset adjustment incorporated into the result was 20.987 mV.

TABLE 2(a) Offset Assembly Sensor Electronics Gain Factoring OffsetAdjustment No. Shaft ID ID ID (mV/Nm) (1) (R²) (mV) (2) (mV) (3) 1 506(M) 105 (M) 398 (M) 2.0006 0.99971 2479.013 0.00 2 502 105 (M) 398 (M)2.0340 0.98330 2470.263 8.749 3 503 105 (M) 398 (M) 2.0289 0.985742840.340 −1.328 4 504 105 (M) 398 (M) 1.9977 1.00117 2471.673 7.340 5505 105 (M) 398 (M) 2.0210 0.98960 2480.449 −1.436 6 507 105 (M) 398 (M)2.0109 0.99457 2469.583 9.430 (1) Target slope for torque sensorassembly system is 2.0 mV/Nm. (2) Reference offset for torque sensorassembly system is 2,500 mV. (3) Calculated from an actual referenceoffset of 2,479.013 mV.

TABLE 2(b) Gain Offset Assembly Sensor Electronics (mV/Nm) FactoringOffset Adjustment No. Shaft ID ID ID (1) (R²) (mV) (2) (mV) (3) 1 506(M) 105 (M) 398 (M) 2.0006 0.99971 2479.013 0.00 2 506 (M) 101 398 (M)2.0072 0.99641 2476.559 2.453 3 506 (M) 102 398 (M) 2.0136 0.993232472.893 6.120 4 506 (M) 103 398 (M) 2.0094 0.99531 2483.848 −4.835 5506 (M) 104 398 (M) 1.9561 1.02245 2451.617 27.396 6 506 (M) 106 398 (M)2.0138 0.99316 2471.111 7.902

TABLE 2(c) Gain Offset Assembly Sensor Electronics (mV/Nm) FactoringOffset Adjustment No. Shaft ID ID ID (1) (R²) (mV) (2) (mV) (3) 1 506(M) 105 (M) 398 (M) 2.0006 0.99971 2479.013 0.00 2 506 (M) 105 (M) 3991.9928 1.00361 2475.357 3.655 3 506 (M) 105 (M) 401 1.9966 1.001712475.678 3.335 4 506 (M) 105 (M) 403 1.9993 1.00034 2476.464 2.549 5 506(M) 105 (M) 404 2.0083 0.99586 2478.658 0.355 6 506 (M) 105 (M) 4052.0020 0.99899 2477.096 1.917

In practical terms, the master system may be, for example, a fullyassembled torque sensor system used by a customer in one of itsproducts, e.g., a gear box for an automobile. When one of the threecomponents needs to be replaced, a new component could be ordered andswapped for the old component. The data in Tables 2(a), 2(b), and 2(c)would be useful in recalibrating the newly paired combination ofcomponents by updating software associated with the system.

Table 3 shows the measured data for the pairing of shaft component IDNo. 503 with magnetic field sensor component ID No. 102 and electroniccomponent ID No. 401. This pairing of components in a fully assembledtorque sensor system was found to exhibit the characteristics as shown,i.e., a gain of 2.0393 mV/Nm with a factor (R²) of 0.9807, and an offsetof 2,470.886 mV at zero applied torque, which produces an offsetadjustment (relative to the master system) of 8.127 mV. Various otherpairings of existing and future-made components, in combination witheach other and with the reference components, could be determined in themanner described above, and the results maintained in a database forfuture reference when customers need to swap components. The databasemay be accessed directly via a desktop terminal or through a wirelessdevice, such as a barcode scanner with wireless capabilities.

TABLE 3 Offset Assembly Sensor Electronics Gain Factoring OffsetAdjustment No. Shaft ID ID ID (mV/Nm) (R²) (mV) (mV) 3-3-3 503 102 4012.0393 0.9807 2470.886 8.127

I claim:
 1. A method comprising: receiving a rotatable shaft or diskcomponent, a magnetic field sensors component, an electronics component,and a software stored in a physical media device, wherein each of thecomponents is adapted for use in a torque sensor system, and wherein thesoftware media device is integral to the electronics component or isintegral to an electronic control unit; receiving information associatedwith the rotatable shaft or disk component, wherein the informationcomprises one or more correction factors; receiving informationassociated with the magnetic field sensors component, wherein theinformation comprises one or more correction factors; assembling thetorque sensor system by at least positioning the magnetic field sensorscomponent near the shaft or disk component, and electronicallyconnecting the magnetic field sensors component to the electronicscomponent; and calibrating the assembled torque sensor system byupdating the software using the received information associated with theshaft or disk component and the received information associated with themagnetic field sensors component, wherein the updated software includesat least an updated gain and an updated offset value based on the one ormore shaft or disk correction factors and the one or more magnetic fieldsensors correction factors.
 2. The method of claim 1, wherein thecorrection factors for each of the shaft or disk and the magnetic fieldsensors components are selected from two or more of the group consistingof a measured sensitivity value, an offset value, a compassing value, ora near field interference value.
 3. The method of claim 1, wherein thecorrection factors for each of the shaft or disk or magnetic fieldsensors components are electronically retrievably stored in anelectronic storage device attached to the respective component.
 4. Themethod of claim 3, further comprising retrieving the characteristicvalue from the electronic storage device and inputting the same in thesoftware.
 5. The method of claim 1, wherein the correction factors foreach of the shaft or disk or magnetic field sensors components areprovided on a surface of the component or on or in a package used totransport the component.
 6. The method of claim 1, wherein the shaft ordisk component comprises first and second oppositely circumferentiallymagnetized sensing regions for outputting respective first and secondmagnetic fields useful in determining an amount of torque applied to theshaft or disk component.
 7. The method of claim 6, wherein the magneticfield sensors component comprises one or more magnetic field sensorsarranged proximate to the shaft or disk component for sensing the firstand second magnetic fields, and the outputted signal is indicative of atorque applied to the shaft or disk component.
 8. The method of claim 1,wherein the electronics component comprises one or more logic circuitsfor receiving a signal from the magnetic field sensors componentindicative of a torque applied to the shaft or disk component and foroutputting a second signal.
 9. The method of claim 1, furthercomprising: manufacturing the one or more of the shaft or diskcomponent, the magnetic field sensors component, and the electronicscomponent at a manufacturing location; and shipping the manufacturedcomponent to an assembly location different than the manufacturinglocation.